"Unvaccinated people will develop a variant that evades vaccines"

Honest question. If it’s just a straight line extrapolation from Covid cases to variant production, why isn’t the USA the world leader in nasty variants? We have the most cases, we should be the perfect petri dish for nasty variants. Yet one of the leading variants is South African, which has 5% of the total cases of USA. Why isn’t there a New York variant, a Florida variant, a Texas variant?